MATH!!!

[ChronoCrosS]

Correct, and you remembered the c!

 

pretty sure you use eulers formula for that one.

 

 

 

 

 

 

 

[WWWwombat]

  Quote

Correct, and you remembered the c!

 

pretty sure you use eulers formula for that one.

 

 

 

 

 

 

 

 

Yep kinda.  Or you could just do what they teach in physics courses and make a good guess.  I don't like guessing much though.

[WWWwombat]

Find the eigenvalues of the matrix:

 

[4 0 1 5 6]

[0 2 1 0 1]

[0 0 0 0 5]

[0 0 0 1 2]

[0 0 0 0 2]

 

There is a really easy way to do this and a harder way to do it.

[Reyoru]

  Quote

Find the eigenvalues of the matrix:

 

[4 0 1 5 6]

[0 2 1 0 1]

[0 0 0 0 5]

[0 0 0 1 2]

[0 0 0 0 2]

 

There is a really easy way to do this and a harder way to do it.

 

OK, this ones out of my depth. What on earth is an eigenvalue?

[ChronoCrosS]

4 2 0 1 2 they are.

 

*loves Matlab*

 

I forgot the easy method to to it. I know the determinant way though.

[Locke]

Wow.  This really  took off :D

[WWWwombat]

  Quote

4 2 0 1 2 they are.

 

*loves Matlab*

 

I forgot the easy method to to it. I know the determinant way though.

 

The eigenvalues of an upper triangular matrix are just the diagonal entries xD

[ChronoCrosS]

Ahh, k got it.

 

Anyone here use Matlab? It works wonders.

[WWWwombat]

  Quote

  Quote

Find the eigenvalues of the matrix:

 

[4 0 1 5 6]

[0 2 1 0 1]

[0 0 0 0 5]

[0 0 0 1 2]

[0 0 0 0 2]

 

There is a really easy way to do this and a harder way to do it.

 

OK, this ones out of my depth. What on earth is an eigenvalue?

 

Say you have a linear transformation T.  An eigenvector is a non-zero vector v such that Tv = λv for some scalar λ.  λ is called an eigenvalue.

[WWWwombat]

I've heard good things about Matlab, Maple, and Mathematica, but all I use is my TI-83 plus and Excel.

[Reyoru]

Cool

[WWWwombat]

Invert the matrix:

 

[-1 0 0]

[ 1 1 1]

[ 1 1 2]

[Reyoru]

Ah, I can invert 2x2 matrices, but I don't know how to calculate the determinant for 3x3

[ChronoCrosS]

[-1 0 0 ; 1 2 -1 ; 0 -1 1]

 

That one was long, so I did it with MAtlab again. I know how to do it with determinants, but I can't remember the other way of doing it...

[Reyoru]

Lol llow this maths. All about medicine :D

[WWWwombat]

A cool method of inverting a matrix is to augment it with the identity on the right and then row reduce.  If the original matrix is invertible, the left half will now be the identity and the right half will now be the inverse.

[Reyoru]

Sweet, that is a neat trick.

 

It beats working out the determinant.

[ChronoCrosS]

  Quote

A cool method of inverting a matrix is to augment it with the identity on the right and then row reduce.  If the original matrix is invertible, the left half will now be the identity and the right half will now be the inverse.

 

That's the way I used to know, I just forgot if there was a way to do it shorter.

[WWWwombat]

  Quote

Sweet, that is a neat trick.

 

It beats working out the determinant.

 

For 3x3 and above yeah.  There's also a way to do it with cross products for 3x3 matrices.

[Locke]

Sometimes I just like to sit down and think about math and patterns and whatnot.  I managed to make up two formulas involving squares and cubes doing that. :D

[Al Jenn Mael]

Well it's been a few years since I've played with linear algebra. I've always liked related rates the most followed by linear algebra. The two are so practical. Differential Equations I didn't like in the least nor did I like non-euclidean geometry. I hate approximations and statistics, but they can be useful especially in modeling molecular constitutes.

 

Well here is one,

 

y"+2y'+2y=0    y(pi/4)=2 y'(pi/4)=-2 

[Al Jenn Mael]

Actually scratch that last one, I have a math question for Seanie:

 

e^πi+6.66+(Sin²(x)+cos²(x))/3=?

 

[Edit]

Fixed the 'E', Thank you Crono.

[ChronoCrosS]

The first one is easy and I know the second one too, but I won't give it away. Shouldn't you use a small 'e' for the second question?  ;)

[Reyoru]

Well as I'm currently half way through a C4 paper, I'm sick of maths XD

Ill do your questions at some point though ;)

[Al Jenn Mael]

Well the first one I don't care who answers ;p

 

The second one with E^pi*i is for Seanie :D